Orthopedic implants are well known in the art. Common orthopedic implants are associated with, for example, the spine, spinal articulations, intervertebral discs, facet joints, shoulder joints, knee, hip and shoulder, elbows, wrists, hands, finger joints, ankles, wrists, feet and toe joints.
Clinical reports of more modernized titanium interbody fusion devices, cages, have demonstrated low subsidence as compared to earlier titanium interbodies. Upon closer examination of the historical and modernized titanium interbodies, a large discrepancy in surface contact area to the endplates can be noted. The smaller contact surface of presently available implant devices to the endplates result in increased adjacent bone surface area pressure, which in turn caused mechanical subsidence of the device. The subsidence issue was partially solved by plastic interbodies, such as Polyetheretherketone (PEEK) or PEAK. Currently available plastic interbodies have thicker walls, required to produce appropriate device strength characteristics. This also gives the plastic devices an increased surface contact area, reducing the surface pressure and likely playing a key role in limiting clinical subsidence. However, thinner walls are preferred to allow for increased bone graft volume.
Thus there exists a need for a new orthopedic device that prevents subsidence, while at the same time, allows for easy and increased bone grafting.